1. Field of the Invention
The present invention relates to a rotation control device for controlling rotation of a disk-shaped recording medium, a method thereof, a program thereof, a recording medium storing the program, and an information processing apparatus.
2. Description of Related Art
There is a conventionally known art for rotating a disk-shaped recording medium, on which information is recorded by a constant linear velocity (CLV) system, with constant linear velocity to read the information by a reader (Refer to, for example, prior art: JP2000-132851A).
In this prior art, a spindle motor for rotating the recording medium is servo-controlled according to signals such as a synchronization signal and a sub-code signal read from the recording medium.
In such art for rotating the recording medium with constant linear velocity, since information reading is stably performed without any error-rate change, its control structure can be simplified. On the other hand, the rotational velocity varies according to a record position of information to be read in the recording medium. Therefore, the eccentricity also varies during rotation, and that puts the load on reading operation such as tracking control. Besides, the spindle motor needs to be variably driven in order to rotate the recording medium with constant linear velocity according to variation of the eccentricity. Depending on the value of the eccentricity, the consumption current for driving the spindle motor increases, so that the heat release from the spindle motor also increases. That might adversely affect the reader located adjacent to the spindle motor.